Elections are being held in Tanzania that will decide whether the ruling party will continue its 54-year rule or give way to a new coalition.
Final rallies were held on Saturday ahead of Sunday's presidential and parliamentary elections.
opinion polls have put the ruling Chama Cha Mapinduzi (CCM) party ahead, but our correspondent in Tanzania says the result is expected to be close.
Four opposition groups are backing one candidate, a former CCM member.
Some of the major issues for the almost 23m registered voters include access to clean water, improved health care and better education, the BBC's Sammy Awami reports from the commercial capital, Dar es Salaam.
President Jakaya Kikwete, who is standing down after two terms, has called for peace ahead of the election, adding that "anyone who tries to cause trouble will be dealt with".
The CCM was formed in 1977 from a merger of two post-colonial parties and has effectively been in power since independence in 1961.
The main presidential candidates
* John Magufuli - Chame Cha Mapinduzi party
Tanzania's works minister, Mr Magufuli, 55, has promised change and to improve on the pace of progress laid down by the previous CCM government.
He has promised to end the country's power shortages and exploit Tanzania's natural gas discoveries.
"My government will put emphasis on fighting corruption, job creation and industrialisation," he said on Saturday.
He is nicknamed The Bulldozer for driving a programme to build roads across the country.
* Edward Lowassa - Ukawa coalition
Mr Lowassa, 62, decided to leave the CCM when it did not pick him as its presidential candidate earlier this year. Four opposition parties rallied behind Mr Lowassa as a coalition candidate.
"We must stop being a nation of beggars," he told a rally on Saturday. "It is a shame for Tanzania to still be poor after 54 years of independence."
He has already served as prime minister, but had to resign over a corruption scandal in the energy sector. He continues to deny involvement in the scandal.
(BBC)